Method and system for controlling electric printout mechanisms

ABSTRACT

Logic circuits cause one type-bar of the printout mechanism to be operated only upon completion of the operation of a previous type-bar. Logic circuits, consisting of differentiating means and monostable multivibrators cause a repeat signal for activating the same type-bar to be activated if a control signal, signifying movement of the type-bar, is not received within a predetermined time period of a first activation signal. Logic means also prevent activation of a type-bar if a machine function such as a space bar operation or a backspacing is taking place. Also, the interval between activation of type-bars is lengthened when the same type-bar is to be activated successively.

United States Patent METHOD AND SYSTEM FOR CONTROLLING ELECTRIC PRINTOUT MECHANISMS 20 Claims, 1 Drawing Fig.

u.s.c| .i 34mins, l0l/93 Int.Cl U 541 9/26 FleldolSearcli 340/1725; 101/93 [56) References Cited UNITED STATES PATENTS 2,717,686 9/l955 Seeber, Jr i. 197/7 2,850, l 36 9/1958 Seeber. Jr. et a]. H 197/7 Primary Examiner-Gareth D. Shaw Assistant Examiner- Paul R. Woods ArmrneyMichael S. Striker ABSTRACT: Logic circuits cause one type-bar of the printout mechanism to be operated only upon completion of the operation of a previous type-bar. Logic circuits, consisting of differentiating means and monostable multivibrators cause a repeat signal for activating the same type-bar to be activated if a control signal. signifying movement of the type-bar, is not received within a predetermined time period of a first activation signal. Logic means also prevent activation of a type-bar if a machine function such as a space bar operation or a backspacing is taking place Also, the interval between activation of typebars is lengthened when the same type-bar is to be activated successively.

PATENTEUNBVQOIQYI 3.624.612

INVENTOR U K/m 90's,

ATTORNEYS METHOD AND SYSTEM FOR CONTROLLING ELECTRIC PRINTOUT MECHANISMS BACKGROUND OF THE INVENTION This invention relates to methods and arrangements for controlling the type-bars of electric printout mechanisms in such a manner that the activation of one type-bar depends upon completion of the action of the previous type-bar.

The writing speed of modern printout mechanisms, as for example electric typewriters, is very high. However, it is limited by a number of factors. For example, the inertia of a type bar necessitates that a relatively long time interval passes between subsequent energization of the same type-bar. If an insufficient time interval elapses between reactivation of the same type-bar, or even activation of type-bars in close proximity to one another the result is improper operation. A further limitation on writing speed is of course that the typewriter carriage must have enough time to complete any required movement between successive type-bar operations.

Several methods are known, whereby it has been attempted to decrease the above-mentioned difficulties. For example, in electric typewriters controlled by data-processing readout equipment, it is now common practice to compare the last written code which has been stored in a storage, with the code signifying the subsequent type-bar to be activated. If the codes are different, the type-bar corresponding to the second code is activated immediately. However, if the two codes are the same, a delay circuit comes into being, which delays the activation of the second type-bar by a predetermined amount. Such a switching arrangement is relatively expensive and must furthermore use the maximum necessary delay as basis.

SUMMARY OF THE INVENTION This invention constitutes a method for controlling electric printout mechanisms having type-bars movable between inoperative and operative positions. It comprises the step of generating a control signal during the movement of any typebar between said operative and inoperative positions. It further comprises the step of generating an activation signal, to permit activation of a subsequent type-bar, in dependence on receipt of said control signal.

BRIEF DESCRIPTION OF THE DRAWING The FIGURE is a block diagram of the logic circuitry for controlling the printout mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the single FIGURE, it is assumed that the electric printout mechanism, here an electric typewriter, which is to be controlled is coupled to a data-processing system and receives pulses from the readout device of said dataprocessing system. The typewriter functions, namely, switching on and off, carriage return, tabulate, blank space, backspace, shifting from small to capital letters, and ribbon lifting, yield a signal on lines 81 to S6, that is, each completed function of the typewriter generates a signal which is applied to OR-gate O! and monostable multivibrator Ml, with exception of the line S5 which represents a blank space, and which is connected to the multivibrator only and also with exception of line $6 on which a control signal is generated when the ribbon has been lifted. In the operation of this circuit, it must be assumed that monostable multivibrator Ml has a determined time constant; that is, the output signal of M] has a definite duration in time. If now a shift signal is received on line S], that is a signal indicating that only capital letters could be printed for the time being, then the output time constant of multivibrator M1 is not sufficient, and amplifier V1 is controlled by the trailing edge of the signal 81. In this example, a signal arriving over input S6 can also become efiective, when a key is depressed. The same is true for a carriage return signal which also has a longer time constant than does multivibrator M I. It is seen that the signals to the inputs of OR-gate O! can have quite different time constants. The control signal 56 further is applied to the set input 8 of a first bistable circuit, namely flip-flop FF3. The reset input R of this flip-flop FF3 is connected to output line 7 by means of line 26. Output line 7 leads to a decoding matrix, which controls the magnets which are associated with the type-bars.

Pulses, which are generated by readout means, said readout means being adapted to derive information from, for example, a punched tape, are introduced to the circuit at the input E after passing through a decoding matrix which is not shown. They are conducted to the set input 5 of a third bistable circuit, namely flip-flop FFI, by means of line 8. The input pulses are further conducted to AND'gate U1 by line 9. Line l0 connects the set input of flip-flop FF 1 with the output of a second amplifier, namely amplifier V4, whose function will be further described below. The reset input R of flip-flop FF] is connected to the output line 7 by means of line 37. The L-output of flip-flop FFl is connected by line 38 to the input of AND- gate Ul, while the O-output is connected to the input ofAND- gate U2 by means of line 29. It should be noted that AND-gate Ul is controlled by positive or l "signals while AND-gate U2 is controlled with negative or "O" signals. Two equal inputs cause the AND gates to furnish an output.

The output of a first monostable multivibrator M1 is connected to the input of OR-gate 01 by means of line 32. The output of 0R-gate OI is connected to the circuit point 45 by means of line 43. A line 23 connects the circuit point 45 to the reset input R of a second bistable circuit, namely flip-flop FF2, the set input S of which is connected by line 22 to the output ofa fifth amplifier, namely V5. With regard to this amplifier, it should be noted that it serves to control a perforator which may be associated with the electrically controlled typewriter of the present invention. It must be noted that the presence of this perforator is not essential to this invention. However, it should be noted that amplifier V5 serves the same purpose for the perforator as amplifier V3 does for the typewriter. Specifically this purpose is to furnish a signal which permits the energizing or activation of the particular punch which corresponds to the code signal which has been selected. The amplifier output of amplifier V5 controls only flip-flop F F2. It is noted that this output sets flip-flop FF2 and the resulting output on line 44 is the signal which frees the selected punch for activation. Amplifier V5 is not associated with the blocking of amplifier VI. The circuit point 45 is also connected, by means of lines 24 and 28, to a circuit which is not shown, which prevents a manual stop during the operation of the circuit. By means of lines 24 and 25 a blocking signal is applied to amplifier V4 from the circuit point 45. Amplifier V1 is activated over line 46 from OR-gate 01.

The output of amplifier V1 is connected to the input of AND-gate U] by means of line 41. The output of AND-gate Ul is connected to the input ofa second multivibrator, namely multivibrator M2 by means of line 42. The output of multivibrator M2 is connected to line 2] and line 18, so that pulses generated by this multivibrator serve as input to a third amplifier V3 and also activate differentiating means DI under predetermined circuit conditions.

The output of differentiating means D1 is connected to the input of a third monostable multivibrator M3 by means of line 17. This multivibrator activates a fourth amplifier, V2, by means of lines 15 and 14 and also serves to energize the manual stop inhibiting circuit via line 16. The output of fourth amplifier V2 activates second differentiating means D2 and also provides an input to AND-gate U1 via line 13. The output of the differentiating means D2 serves as input to a second amplifier V4 to which it is connected by line ll. The output of this amplifier V4 is connected to the set input S of the previously mentioned flip-flop FF 1.

The following operations occur by means of the abovedescribed circuitry:

The flip-flops FFl, FF2, and FF3 are reset by means of a manual signal on line 36. This causes the readout means, not shown, to be energized via line 29 and AND-gate U2. The

readout pulses are entered at input E and reach the set input S offlipsflop FFl by means ofline 8. They also serve as input for AND-gate U] by means of line 9. The switching of flip-flop FFl results in a pulse appearing at its L-output which energizes multivibrator M2 over line 42. The output of multivibrator M2 controls the output amplifier V3 by means of lines 2! and 18. The output amplifier V3 in turn conducts the information signals readout from the readout to the decoding matrix associated with the type-bars, by means of line 7. The signal on line 7 is a signal permitting activation of the type-bar selected by the decoding matrix output. The output signal appearing on line 7 energizes amplifier V5 by means of lines 39 and 33 and, if this amplifier is not blocked by means of signals PC or 2U both flip-flop FF! and flip-flop FF3 will be reset, so that the amplifier V! is also blocked. At this time, the type-bar has become activated by the code pulses furnished to the decoding matrix by line 7, and the type-bar begins to move from its inoperative to its operative position. Simultaneously, the ribbon is lifted, which causes a contact to close which causes a pulse to be applied to the input S of F F3 by means of line 86. This pulse is also supplied to the multivibrator Ml. This causes flip-flop FF3 to switch to the set position, thus removing the blocking signal of amplifier V1. The pulses appearing at the output of multivibrator M1 activate OR-gate Di and the amplifier V] by means of line 43 and 46. It should further be noted that circuit point 45 is negative when no signal Sl-S6 is present. thereby blocking amplifier V4 as well as amplifier Vl. Further, the l output of flip-flop FF3 may be used to block amplifier V3. The reset input R of fiip flop F F2 is energized from circuit point 45, while amplifier V4 is blocked over lines 24 and 25. Furthermore, a circuit prevent ing the manual stopping of the circuit operation is energized over lines 24 and 28. A manual input to the machine could stop the operation of the automatic circuitry at a time when a type-baris, for example, being moved from the inoperative to the operative position. It is a purpose of the signal on line 28 to prevent a manual overriding of the automatic circuit operation at selected times in the operating cycle. The switching of FF2 results in a removal of the blocking voltage present at differentiating means Dl, so that the output of amplifier Vl energizes multivibrator M2 via AND-gate Ul. The output of multivibrator M2 now goes to the difi'erentiating means D1. The output of differentiating means Dl activates multivibrator M3 over line 17. Multivibrator M3 in turn energizes amplifier V2 over lines and 14. The manual stop inhibiting circuit is again energized over line 16. The output signals of amplifier V2 are conducted to AND-gate U] by line 13 and are further conducted to difi'erentiating means D2 by line 12.

When the voltage at circuit point 45 has gone, amplifier V4 is opened and is thus activated by the output of differentiating means D2. Amplifier V4 is turn furnishes a repeat signal which is applied to the set input S of flip-flop FFl. The L-output of flip-flop FF] in turn is applied to AND-gate U1 which activales multivibrator M2 and thus the third amplifier, or out put ampIifier'VS. The output signal on line 7 of amplifier V3 in turn causes flip-flops FFl and FF3 to be reset by means of lines 37 and 26 respectively. Furthermore. a signal on line 7 causes flip-flop FF2 to be set, by means of amplifier V5 if said amplifier is not blocked by signals PC and/or 2U. Differentiating means D1 which may be a circuit as shown in U.S. Pat. No. 3,l97,6l8 (Stanely and von Kummer), FIG. 48 (863455]! 863-852) and described in section 34, line 53 et seq. in said patent, is then blocked by means of the L-output of flip-flop FF2. Line 44, extended, leads to an associated punching mechanism. The following output signals from multivibrator M2 energize amplifier V3 and thence the decoding matrix as described above. It may be seen from the above-described discussion that the circuit of this invention causes a type-bar to be activated to move from its inoperative to its operative position only when the movement of a previous typebar has been completed, thus eliminating any unwanted interaction between the type-bars.

While the invention has been illustrated and described as embodied in a circuit using particular logic elements, it is not intended to be limited to the details shown, since various modifications and circuit changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential features of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning the range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

I. A method for controlling electric printout mechanisms having type bars movable between inoperative and operative positions, comprising, in combination, the steps of furnishing an input signal selecting a type-bar; energizing said type-bar; generating a control signal in dependence on the movement of said type-bar between said inoperative and operative positions; and generating an activation signal for moving a subsequent type-bar in dependence on receipt of said control signal.

2. A method as set forth in claim 1, also comprising the step of reenergizing a type-bar, if said type-bar has not moved from said inoperative position to said operative position within a predetermined time period, after generation of said activation signal.

3. In an electric printout mechanism having type-bars mova ble between inoperative and operative positions, a control system, comprising, in combination, input means furnishing an input signal signifying the selection of a type-bar; means for energizing said type-bar; means for generating a control signal in dependence on the movement of said typebar between said inoperative and operative positions; and energizing signal furnishing means for generating an energizing signal permitting movement ofa subsequent type-bar in dependence on receipt of said control signal.

4. A system as set forth in claim 3, further comprising a data-processsing system having a decoding arrangement generating decoded signals; wherein said data-processing system further comprises means for generating function signals as a function of operations carried out by said printout mechanism; also comprising logic means for accepting said decoded signals and controlling the transmission of said decoded signals to said means energizing for said type-bars in dependence on said function signals.

5. A system as set forth in claim 4, wherein said control signal is applied to the input ofa monostable multivibrator and to the SET input ofa first bistable circuit.

6. A system as set forth in claim 5, wherein said function signals are applied to the input of said monostable multivibrator.

7. A system as set forth in claim 6, also comprising an OR gate connected to the output of said multivibrator.

8. A system as set forth in claim 7, also comprising a first amplifier connected to the output of said OR gate at a first circuit point.

9. A system as set forth in claim 7, wherein said first amplifier is connected to said bistable circuit in such a manner that said amplifier is blocked when said bistable circuit is in the RESET position.

10. A system as set forth in claim 9, also comprising a second bistable circuit; and wherein said first circuit point is connected to the RESET input of said second bistable circuit.

11. A system as set forth in claim [0, also comprising circuit means for impeding a manual stop signal; and also comprising a second amplifier; wherein said first circuit point is connected to said manual stop impeding circuit and to a blocking input of said second amplifier.

[2. A system as set forth in claim 10, also comprising an AND gate, the output of said AND gate being determined sub stantially by the decoded signals.

13. A system as set forth in claim 12. also comprising a second monostable multivibrator and a third amplifier; wherein the input of said second multivibrator is connected to the output of said AND gate, while the output of said second multivibrator is connected to the input of said third amplifier,

14. A system as set forth in claim [3, also comprising means for blocking said third amplifier in the presence of said control signal.

15. A system as set forth in claim 13, also comprising differentiating means differentiating the output of said second multivibrator, when said control signal is present at the SET input of said first bistable circuit.

16. A system as set forth in claim 15, also comprising a third monostable multivibrator adapted to receive the output of said differentiating means, and adapted to furnish a monostable output signal; also comprising a fourth amplifier adapted to receive said monostable output signal and furnish an amplified monostable output signal; and wherein said monostable output signal energizes said manual stop prevention circuit 17. A system as set forth in claim 16 also comprising second differentiating means connected in such a manner that said amplified monostable output signal is differentiated when said control signal at said SET input of said first bistable circuit has died down.

18. A system as set forth in claim 18. also comprising a third bistable circuit having a SET input connected to the output of said second amplifier.

19. A system as set forth in claim 13, also comprising a fifth amplifier connected to the output of said second multivibrator. and having an output connected to the SET input of said second bistable circuit.

20. A system as set forth in claim 19, also comprising means for connecting the L-output of said second bistable circuit to said first differentiating means in such a manner that said first differentiating means is blocked when a signal appears on said L-output. 

1. A method for controlling electric printout mechanisms having type bars movable between inoperative and operative positions, comprising, in combination, the steps of furnishing an input signal selecting a type-bar; energizing said type-bar; generating a control signal in dependence on the movement of said type-bar between said inoperative and operative positions; and generating an activation signal for moving a subsequent type-bar in dependence on receipt of said control signal.
 2. A method as set forth in claim 1, also comprising the step of reenergizing a type-bar, if said type-bar has not moved from said inoperative position to said operative position within a predetermined time period, after generation of said activation signal.
 3. In an electric printout mechanism having type-bars movable between inoperative and operative positions, a control system, comprising, in combination, input means furnishing aN input signal signifying the selection of a type-bar; means for energizing said type-bar; means for generating a control signal in dependence on the movement of said type-bar between said inoperative and operative positions; and energizing signal furnishing means for generating an energizing signal permitting movement of a subsequent type-bar in dependence on receipt of said control signal.
 4. A system as set forth in claim 3, further comprising a data-processsing system having a decoding arrangement generating decoded signals; wherein said data-processing system further comprises means for generating function signals as a function of operations carried out by said printout mechanism; also comprising logic means for accepting said decoded signals and controlling the transmission of said decoded signals to said means energizing for said type-bars in dependence on said function signals.
 5. A system as set forth in claim 4, wherein said control signal is applied to the input of a monostable multivibrator and to the SET input of a first bistable circuit.
 6. A system as set forth in claim 5, wherein said function signals are applied to the input of said monostable multivibrator.
 7. A system as set forth in claim 6, also comprising an OR gate connected to the output of said multivibrator.
 8. A system as set forth in claim 7, also comprising a first amplifier connected to the output of said OR gate at a first circuit point.
 9. A system as set forth in claim 7, wherein said first amplifier is connected to said bistable circuit in such a manner that said amplifier is blocked when said bistable circuit is in the RESET position.
 10. A system as set forth in claim 9, also comprising a second bistable circuit; and wherein said first circuit point is connected to the RESET input of said second bistable circuit.
 11. A system as set forth in claim 10, also comprising circuit means for impeding a manual stop signal; and also comprising a second amplifier; wherein said first circuit point is connected to said manual stop impeding circuit and to a blocking input of said second amplifier.
 12. A system as set forth in claim 10, also comprising an AND gate, the output of said AND gate being determined substantially by the decoded signals.
 13. A system as set forth in claim 12, also comprising a second monostable multivibrator and a third amplifier; wherein the input of said second multivibrator is connected to the output of said AND gate, while the output of said second multivibrator is connected to the input of said third amplifier.
 14. A system as set forth in claim 13, also comprising means for blocking said third amplifier in the presence of said control signal.
 15. A system as set forth in claim 13, also comprising differentiating means differentiating the output of said second multivibrator, when said control signal is present at the SET input of said first bistable circuit.
 16. A system as set forth in claim 15, also comprising a third monostable multivibrator adapted to receive the output of said differentiating means, and adapted to furnish a monostable output signal; also comprising a fourth amplifier adapted to receive said monostable output signal and furnish an amplified monostable output signal; and wherein said monostable output signal energizes said manual stop prevention circuit.
 17. A system as set forth in claim 16, also comprising second differentiating means connected in such a manner that said amplified monostable output signal is differentiated when said control signal at said SET input of said first bistable circuit has died down.
 18. A system as set forth in claim 18, also comprising a third bistable circuit having a SET input connected to the output of said second amplifier.
 19. A system as set forth in claim 13, also comprising a fifth amplifier connected to the output of said second multivibrator, and having an output connected to the SET input of said seCond bistable circuit.
 20. A system as set forth in claim 19, also comprising means for connecting the L-output of said second bistable circuit to said first differentiating means in such a manner that said first differentiating means is blocked when a signal appears on said L-output. 